Masala is the Hindi word for spice. Masala also indicates the collective spices that are blended together to create a variety of Indian dishes.

The key to masala is in knowing the correct proportion of spices needed to create a blend that will produce the desired taste.  Once the masala is blended, creating a delicious curry is actually quite simple, for there are only a few, simple techniques that must be employed – frying onions to a dark brown and frying the spices first to allow the flavors to release and infuse the oil.

Cooking Indian is not an exact science; it is a highly diverse cuisine, as vast and diverse as the country itself.  Every region of India has developed a different cuisine, shaped by its history, customs and locally grown foods. Cooks create distinctive flavors by blending different combinations of spices with local ingredients.

Cooking traditions vary.  For instance, in the North, dry, ground spices are added to cooking, while in the South, whole spices are ground and made into a paste by combining browned onions and other ingredients, creating a "wet masala".  Northern Indians tend to serve more roti (wheat-based breads), while the South is distinguished by a greater emphasis on rice as the staple grain.  North Indian cuisine is known for its heavy use of dairy – cream, paneer, ghee (clarified butter), and yogurt.  Curries are typically dairy-based.  South Indian cuisine makes heavy use of coconut milk and has a greater infusion of tamarind, curry leaves, hot chilies and mustard seeds.

Origins of the word curry
The origin of the word curry is from the Tamil word ‘kari’ meaning sauce. The experts seem to agree that the word originates from India and was adopted by the British Raj.  In the West, the word curry is traditionally thought to be synonymous to Indian food or is characterized by the type of curries popularized by restaurants. There are many different varieties of "curry", each representative of a different regional cooking style.  

What is authentic Indian food

India is an amalgamation of various ethnic groups; over time, these groups left their mark, causing evolution and change in her cuisine.  For example, Goa, on the southwestern coast of India, shows the influences of its Portuguese history. Goans eat pork and duck, meats rarely seen outside the area, and use vinegar as a souring agent, another Portuguese legacy.  Vindaloo, known for its balance of sweet and sour, is the best-known of Goan dishes.  It is made with vinegar, which is not traditionally used in Indian cooking. Take as another example the food of North India.  Its cuisine has been influenced by the Mughals who invaded India in the 16th century.  The Mughals brought with them Persian and Afghan cooks.  The Persian influence is seen in the introduction of new cooking methods; 'Mughlai' dishes such as Kofta, Korma and Pasanda, make heavy use of milk and cream. The use of dried fruit and nuts are characteristic of Persian cuisine as well. The fragrant rice dish biryani (meat-based pilaf) is Persian inspired. 

As you can see, when it comes to Indian cuisine, one must use the term "authentic" quite loosely.  There is a misconception that the popular Indian dishes found on the Indian restaurant menu are authentic Indian food.  More accurate would be to say that these dishes are creations arising from the many cultural influences in India spanning several centuries.